SEN 



SEN 



itshavinpf been formerly burni : in other refpciSs it has the 

 fame properties with tliofe of Kelo't ; which fee. The paf- 

 fage from this ifla..d t ' Tfhirpo Oi is 200 verits. 



SEMYDA, ni Botany^ the name of a tree, mentioned 

 by Theophrallus, and by fome fuppofed to be the fame 

 with the betula, or birch-tree, but very erroneously. 



SEMYSTA, in Ancient Geography, an iflaud of the 

 Britifh ocean, near the coaft of the Ofifmii, in which the 

 Gauls had a celebrated oracle^ according to Pomponius Mela. 



SEMZA, in Geography, a town of Ruffia, in the go- 

 vernment of Archangel ; 16 miles N.N.E. of Mezen. 



SENA, or Mahzali, a town of Africa, in the country 

 of Mocaranga, on the river Zambeza, where the Portuguefe 

 have a faftory. S. lat. 17° 35'. E. long. 35- 20'. 



Sena, Ser.na, or Egyptian CaJJia, in the Materia Medica, 

 a purgative leaf much ufed in draughts and corapofitions of 

 that intention. 



The fhrub which bears it is a fpecies of caJJia ; which fee. 



There is alio a kind of fena growing about Florence ; but 

 it is inferior to that of the Levant, as is owned by the 

 Italians themfelves. Father Plumier mentions alfo a third 

 kind growing in the Antilles iflands. 



M. Lemery diftinguifhcs three forts of fena of the Le- 

 vant : the firit brought from Seyda, called fena of apalto, 

 that is, citflom fena, by reafon of the cuftom paid the grand 

 (ignior, for the privilege of exporting it ; the fecond comes 

 from Tripoli ; the third is called fetia of Mocha. 



Sena is a native of Egypt, the bett of which is faid to 

 grow in the valley of Balabras, or of Nubia : it alfo grows 

 in fome parts of Arabia, efpecially about Mocha ; but as 

 Alexandria has ever been the great mart from which it has 

 been exported into Europe, it has long been dillinguiflied 

 by the name of Alexandrian fenna or fena. 



The belt fena, named in Nubia " guebelly," grows wild, 

 and yields two crops of leaves, the abundance of which de- 

 pends on the periodical rains. The firll crop is collefted 

 after the firft rains, about the middle of September ; the 

 fecond in the following March. The plants are cut down, 

 and expofed on the rocks to dry in the fun. The leaves are 

 then picked, packed up in bales, and fent down to Alex- 

 andria, where they are mixed with two other fpecies of 

 caflia : the one the C fenna of For(]<al, with obtnfe leaves ; 

 the other probably the C. angujlifolia of Willdenow, the 

 leaves of which are longer, narrower, and fiiarpcr pointed 

 than thofe of the proper fena, and come from Mocha. 

 There is reafon alfo for thinking that it is further adul- 

 terated with the leaves of colutea, bladder-fena, and of box. 

 The fena, after being thus mixed, is repacked in bales at 

 . Alexandria, whence it is exported to Europe. 



M. Bh)ndel, who was French conful at fevcral fea-ports 

 of the Levant, informs as, that the true fena grows only in 

 the woods of Ethiopia, and in Arabia; and that the fena, 

 vifhich was brought from Saide and Tripoli, was carried 

 there by the caravans ; and this opinion is llrengthened by 

 the negative tellimony of Alpinus, who, in liis book " De 

 Plantis ./Egypti," does not notice fena. But as Hadel- 

 quifl; found this plant growing fpontaneoudy m Upper 

 Egypt, Blondel's aliertion is not to be implicitly received. 

 Sena appears to have been cultivated in England in the time 

 of Parkinion, A.D. 1640. 



The odour of fena leaves is faint, rather difagreeable, and 

 fickly ; the taile (lightly bitter, fwcetifli, and naufeous. 

 Boiling water extraAs about one-third of the weight of the 

 leaves em[)loyed: the infufion has a deep reddifli-brown co- 

 lour, with the odour and taltc of the leaves. This infufion, 

 when expoled to the atmofphere, depofits a lemon yellow-co- 

 loured iiifohible matter ; and a fimilar precipitate is produced 

 by oxyrauriatic acid, and fevcral other fubltances. Alcohol 



and fulpluiric ether, digefted on the powdered leaves, ac. 

 quire a deep ohve-grcen colour. When tlie ethereal tiniture 

 is poured on the furface of pure water, a dark olive pellicle 

 remains after the evaporation of the ether, which is almoit 

 infipid, and has all the properties of refm ; and a golden 

 colour is communicated to the water. This colour may be 

 produced by fome extraftive being taken up by the ether, 

 clofely united to the refin. The alcoholic tincture is ren- 

 dered only flightly milky by the addition of water, and 

 fcarcely any precipitate is produced; but a copious one is 

 thrown down by oxymuriatic acid. The aAive principle of 

 lena appears to be a very oxidizable cxtraftive, refin, and a 

 peculiar volatile matter; and it contains alfo mucus, and 

 iome faline ingredients. According to Bullion Lagrange, 

 the refidue of the watery infufion evaporated to dryneff, 

 and burnt, yields potafs, fulphate of potafs, carbonate of 

 lime, magnefia, and filica. 



It is in common ufe as a purgative, generally operating 

 under four hours after it is taken ; and is well adapted for 

 all cafes, in which the bowels require certain, but moderate, 

 evacuation (fee Cassia Senna) ; and though it be not eafily 

 accounted for, its bitterncfs aids its operation. To this 

 purpofe Dr. Cullen remarks, that when fena was infufed 

 in the infufum amarum, a lefs quantity of the fena was ne- 

 cefiary for the dofe than the fimple infufion of it. Sena, 

 however, when infufed in a large proportion of water, as a 

 drachm of the leaves to four ounces of water, rarely occafions 

 much pain of the bowels ; and to thofe who do not objeft to 

 the bulkinefs of the dole, may be found to anfwer all the 

 purpofes of a common cathartic, its operation being aided 

 by plentiful draughts of weak broths or gruel. The dofe, 

 in fubftance, is from a fcrnple to a drachm ; in infufion, from 

 one drachm to three or four. It gives out its virtue both to 

 watery and fpirituous menftrua ; communicating to water 

 and proof fpirit a brownifh colour, and to reftificd fpirit, a 

 fine green. The two inconveniences attending the ufe of 

 this medicine, are its being liable, in molt: conllitutions, to 

 occafiou gripes, and its being accompanied with an ill fla- 

 vour, which is apt to naufeate the llomach and palate. 

 The griping feems to be occafioned by the refinous matter, 

 as the infufion made with cold water does not gripe, al- 

 though It purges. The firIt may be greatly obviated by- 

 dilution ; the latter by aromatic and other additions ; e. gr. 

 cinnamon, or a drachm or two of its diltilled water, or car- 

 raway, or cardamom feeds. The decoftion is a bad form 

 in which to adminider this drug, as its aftivity is much im- 

 paired by boiling ; ou-mg, according to Grew, to the total 

 didipation of the nauleous and volatile principles ; but, as 

 Thomfon conceives, to the oxydizement of the extraftive, 

 which alio accounts for the fevere gripings occafioned by 

 the decoilion. 



Several compofitions of this kind arc prepared in the 

 fhops, fufllciently palatable, and which operate for the mod 

 part with cafe and mildnefs. Such are the following : via. 

 confcHion of fena, the cledluary of fena of the Lond. Pli. of 

 1787, and the lenitive eledtuary of P. L. 1745 and 1720. 

 (See Electuaky of Sena.) The Dublin pharmacopeia 

 direfts the eletluary of fena to be prepared by taking of 

 fena leaves, in very fine powder, 4 ounces ; palp of prunes, 

 I pound; pulp c;f tamarinds, 2 ounces ; molallcs, lApint; 

 and ed'ential oil of carraway, 2 drachms. Boil the pulps 

 with the fyrup, to the thicknefs of honey ; then add the 

 powder ; and when the mixture is nearly cold, the oil : 

 finally, mix the whole thorougiily together. 



Thefe eledluaries furnilh a mild and pleafant purgative, 

 and well adapted for thofe who are afflicted with habitual 

 colliveiiefs, and alfo for pregnant women. Tile dofe is 

 from 5j to 3'v, or more, taken at bed-time. 



F f 2 ' E.xtraSl 



